If anybody gets hurt, legally there or not you will find yourself in DEEP POOP here in this country............and maybe in other countries. What is your plan if some kid gets shocked, falls overboard and drowns??? GOOD LUCK!

Better check the laws there. In the US, it's illegal to booby-trap your property in order to keep people out if there's any chance the peson caught would be hurt -- in all 50 states. Someone hits an electrified lifeline, falls in the water, hits his head on the boat he was going to use to carry away YOUR belongings, and drowns, YOU are liable.

That's because, say, an electrified fence can't make judgments the way you would when deciding whether or not to shoot at someone.

It is true, setting a man trap is illegal most places. I am also not a fan of such things, as they often get you, your neighbor trying to save your boat, etc..

There was a case many years ago in the Little River section of Miami. A shopkeeper tired of thieves knocking the windows out every night and stealing him blind, installed bars on the windows and doors. The thieves responded by cutting holes in the roof to enter. This went on night after night, and the police did what they usually do, write reports after every break in.

Tired of fixing his roof every day, he electrified a grid under the roof. His trap caught it's prey on the very first night, and killed a young man. The shop owner was charged with murder.

A Jury of his peers heard his case and refused to convict him. Not a couple of sympathetic Jurors who caused a hung Jury, but an Acquittal of all charges. A foreign yachtsman could hardly count on such sympathy, however.

All of that being said, if a thief gets shocked and hits his head and drowns due to your electrified lifelines, there are questions like, how far can I throw my portable electric fence box? Take the stickers identifying it as an electric fence box off first though, I'm hoping the water will be pretty clear.

We're heading for the Philippines and Indonesia where people like to com on board at night and select things on deck that they feel we no longer want nor need. I had a talk with a fellow cruiser who has electrified his lifelines by keeping a car battery in his cockpit and running one wire into the water and clipping the other to his lifelines. He claims it has worked great at keeping visitors off his boat at night.
Any thought or suggestions on wether this will actually work?

12 volt DC wont deliver any significant shock unless he has some kind of transformer between battery and lifelines to step it up.

Also to get shocked the "shockee" must provide a path to ground via his body...how does this happen standing on a (presumably) fiberglassdeck? For example, an electric fence shocks you because you touch it while standing on the ground...birds can land on it w no shock.

Who came up with these dumb laws? Someone tries to rob you and dies in the process. I don't see the problem here. Someone coming to your aid due to a fire or something - oh yes, you would need warning signs... probably not enough to make it legal though. :-(

12 volt DC wont deliver any significant shock unless he has some kind of transformer between battery and lifelines to step it up.

Also to get shocked the "shockee" must provide a path to ground via his body...how does this happen standing on a (presumably) fiberglass deck? For example, an electric fence shocks you because you touch it while standing on the ground...birds can land on it w no shock.

So long you do not hurt or drown anybody. Your intention to discourage some one by inflicting pain may turn into a mishap that may become more that what you expected to achieve.In Prison in St Lucia

I go for the light and a hooter, in some place the mention of a CCTV in use does discourage, you may have to find the correct translation. Just the noise of few infrared detectors in the dark and little pilot lights shining as often proved to be more than the nerve of an average prowler can withstand. I am may be outdated but in these regions having a friendly cup of tea with some of the important local, harbour, immigration, may be rewarded by a safe stay. Give people some importance they may return it.

Man traps, aka spring traps, great way to get into big trouble in any country that follows English common law traditions. Phillipines? Might still be a bad idea but their legal code won't come from the same roots as the US or the British Empire.

If you will be on board, better to get some motion detectors and hook up an alarm. As long as they are pointing to your deck, not over the side, they won't false alarm. Inexpensive, and legal all over the world.

Doubt it will work. If your SS lifelines are routed through SS stanchions bolted to the deck which is damp and a bit salty you will have a lot of leakage current.

Might be worth a try. Fence controllers generate about 8500V normally and the pulse is a millisec or so long so it won't kill you. Will knock your hand off the line. I never knew anyone who could grab a working fence and hold on to it. You don't have to touch the line to test it. You can buy an electronic fence tester for about 30 bucks at farm supply stores or on line.